The long term objectives of this work are to gain an understanding of the regulation of eucaryotic cell division. In particular, we hope to examine the coordination of synthesis and modification of protein during the cell division cycle of Saccharomyces cerevisiae. The goals for the current year have been l) to examine the change in synthesis and activity of aldolase during the cell cycle, 2) to evaluate the pattern in protein phosphorylation during the cell cycle and, 3) to determine if these patterns are altered following cell cycle arrest using either alpha factor (a yeast mating "hormone" which causes cell cycle arrest in Gl) or conditional lethal temperature-sensitive cdc (cell division cycle) mutants which arrest at various points in the cell cycle at the non-permissive temperature.